ULTEIG Engineers, Inc.

1
Fargos Revised Local Limits and Development of
the Proposed Wastewater Surcharge Program

• ULTEIG Engineers, Inc.
• Thomas J. Welle, P.E.

Consulting Engineers, Planners Land Surveyors
Since 1944 Fargo w Bismarck w Minneapolis w Sioux
Falls
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Local Limits
What are Local Limits? Local Limits (def.)
Conditional discharge limits imposed by
municipalities upon industrial and commercial
businesses that discharge to the POTW (Publicly
Owned Treatment Works).
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Local Limits

• How are Local Limits Established?
• The limits are developed and enforced by POTWs
  with guidance and approval from EPA
• Based upon the maximum loading of pollutants that
  can be accepted by the POTW

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Local Limits

• Why do POTWs Need to Establish Local Limits?
• To meet requirements as listed in the EPAs
  general pretreatment regulations (40 CFR Part
  403)
• To protect the treatment facility against pass
  through or interference
• To protect sanitary sewage collection and
  conveyance systems

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Local Limits

• Why do POTWs Need to Establish Local Limits?
• To prevent adverse impacts on receiving water
  quality
• To prevent interference with beneficial use of
  biosolids
• For Worker health and safety

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Local Limits

• When Should Local Limits be Re-evaluated or
  Revised?
• Changes at the POTW (construction projects)
• Re-evaluation as part of the annual report
• NPDES permit renewal
• Violations of NPDES permit

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Local Limits

• What will Automatically Trigger Action by POTWs
  to Revise or Develop Local Limits?
• When the headworks loading at the POTW is at or
  greater than 70 of the design loading for
  metals, ammonia or toxic organics
• When BOD and TSS loading is at or greater than
  80 of the organic design for the POTW

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Local Limits

• Why has the City of Fargo Revised its Local
  Limits?
• The City of Fargos local limits were first
  developed in 1985 and are always subject to
  review by EPA
• The City of Fargo recently (1991-2000) completed
  a major expansion of its POTW
• The revised local limits were adopted in
• May of 2003

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Local Limits
Categorical Industrial User (def.) CIUs are
subject to categorical pretreatment standards (as
listed in the Code of Federal Regulations 40 CFR
Chapter I, Subchapter N). CIUs are required to
pretreat their wastewater for certain pollutants
to specific numerical values prior to discharging
to a POTW.
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Local Limits

• Significant Industrial User (def.) SIUs are
  those industries not listed as categorical but
  are significant users in one of the following
  ways
• Discharge 25,000 or more gallons of process
  wastewater per day to POTW
• Contribute 5 or more of the average dry weather
  hydraulic or organic load to POTW
• Have potential to adversely affect
• POTW

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Local Limits
What are the City of Fargos Revised Local
Limits for SIUs? Pollutant Concentration
(mg/L) Arsenic (As) 2.8 Benzene 0.05 BETX
0.75 Cadmium (Cd) 0.20 Chromium
(III) 5.86 Chromium (VI) 0.65 Copper
(Cu) 2.82 Chromium (Total) 5.57 Note CIU
Pretreatment Standards are more
stringent than concentrations shown
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Local Limits
What are the City of Fargos Revised Local
Limits for SIUs? Pollutant Concentration
(mg/L) Lead (Pb) 1.6 Mercury
(Hg) 0.001 Nickel (Ni) 5.6 Selenium
(Se) 0.26 Silver (Ag) 2.0 Zinc (Zn)
18.17 pH 5 to 12.5 Note CIU
Pretreatment Standards are more
stringent than concentrations shown
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Local Limits
What are the City of Fargos Revised Local
Limits for SIUs? Allowable SIU Mass Loadings
for BOD and TSS at POTW Total SIU BOD mass
loading 7,353 lbs/day Total SIU TSS mass
loading 4,825 lbs/day
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Local Limits
Questions?
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Fargos Proposed Wastewater Surcharge Program
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Fargos Proposed Wastewater Surcharge Program

• Program Background Information
• Review of existing Categorical Industrial Users
  (CIUs) list and the development of Significant
  Industrial Users (SIUs) list
• What criteria were used by the City of Fargo to
  determine whether an industry or commercial user
  was an SIU?

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Fargos Proposed Wastewater Surcharge Program

• What Criteria were Used for Determining a
  Significant Industrial User (SIU)?
• Discharges 25,000 or more gpd of wastewater
• Contributes 5 or more of the average dry weather
  hydraulic or organic capacity of the POTW
• Has a potential to adversely affect the
• POTW

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Fargos Proposed Wastewater Surcharge Program

• Program Background Information
• Site visits were conducted and samples were taken
  to measure BOD and TSS concentrations
• Current wastewater collection, conveyance and
  treatment expenditures were reviewed

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Fargos Proposed Wastewater Surcharge Program

• Current Unit Cost for Wastewater Treatment in
  Fargo
• Existing Unit Cost 1.40 per 1000 gallons
• Cost includes operation and maintenance
  expenditures for wastewater collection,
  conveyance and treatment. Also includes
• costs for repayment of SRF loan

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Fargos Proposed Wastewater Surcharge Program

• Is the Existing Unit Cost (1.40/1000 gall.) an
  Equitable Way of Charging Industry for Wastewater
  Treatment in Fargo?
• Adequate for treatment of domestic strength
  wastewater (BOD 200 mg/L , TSS 230 mg/L)
• Inadequate unit cost for treatment of high
  strength wastewater

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Fargos Proposed Wastewater Surcharge Program

• Is the Existing Unit Cost (1.40/1000 gall.) an
  Equitable Way of Charging Industry for Wastewater
  Treatment in Fargo?
• Much of the wastewater from SIUs in Fargo is not
  normal domestic strength
• The cutoff between domestic and high strength
  wastewater in Fargo is 275 mg/L for BOD TSS

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Fargos Proposed Wastewater Surcharge Program

• What is an Equitable Way of Charging SIUs for
  Wastewater Treatment in Fargo?
• The fees for SIUs in Fargo should include a unit
  cost for treatment of normal domestic strength
  wastewater
• In addition fees should include a surcharge for
  treatment of wastewater over and above normal
  domestic strength

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Fargos Proposed Wastewater Surcharge Program

• How Will the City of Fargo Determine What the
  Surcharges Should be?
• Expenditures for treatment of BOD and TSS were
  evaluated
• From those expenditures the surcharges for BOD
  and TSS were developed
• The proposed surcharges for BOD and
• TSS are 41/1000 lbs and 50/1000 lbs

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Fargos Proposed Wastewater Surcharge Program

• Program Background Information
• This surcharge program is not unique to the City
  of Fargo
• Comparisons to other regional wastewater
  surcharge programs were made

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Fargos Proposed Wastewater Surcharge Program
Regional Surcharge Comparisons
Note Wastewater Surcharges Shown are Proposed
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Fargos Proposed Wastewater Surcharge Program

• Why Does the City of Fargo Need to Implement a
  Wastewater Surcharge Program?
• The City is limited by industrial mass loadings
  at the head of the POTW
• Industries account for 10 to 15 of the organic
  load on the POTW

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Fargos Proposed Wastewater Surcharge Program
Example SIU Wastewater Charges Example
Data Industry XYZ Monthly
Discharge (gallons) 500,000 BOD
Concentration (mg/L) 1,000 TSS
Concentration (mg/L) 1,500 Load
Calculations BOD Load in Excess of 275 mg/L
(lbs) 3,025 TSS Load in Excess of 275
mg/L (lbs) 5,111 Monthly SIU
Charges Flat Fee (1.40/1000 gallons)
700 BOD Surcharge (41/1000 lbs)
124 TSS Surcharge (50/1000 lbs)
256 Total Charges 1,080
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Fargos Revised Local Limits and Development of
the Proposed Wastewater Surcharge Program

• ULTEIG Engineers, Inc.
• Thomas J. Welle, P.E.

Consulting Engineers, Planners Land Surveyors
Since 1944 Fargo w Bismarck w Minneapolis w Sioux
Falls